As recently as ten years ago, the vast majority of industrial robots were controlled by hard-wired logic electronics and were taught using simple teach and repeat methods. The robot "programs" created consisted primarily of instructions to move the robot to a taught location, generate an output signal, or wait for an external input signal. A typical program would consist of fewer than one hundred such instructions. For the most part, industrial robots were used to spot weld car bodies, spray paint, handle heavy objects, and service process machines such as machine tools, forges, and furnaces. For most of these applications, the simple controls provided with the robots were adequate to perform the required tasks and had the benefit of being easy to understand and program.
The needs of industry have changed, and today the majority of industrial robots sold in the United States are equipped with computer controls and robot programming languages. These new systems offer tremendous computational capabilities, equivalent to those found in conventional high-level computing languages. This computational ability is often combined with flexible input and output control, interfaces to vision systems and other types of sensory input, real-time motion control capability, and network communication facilities.
There has also been a dramatic shift in application emphasis. While spot welding is still the largest robot application segment, the small parts handling and assembly segment is the fastest growing area and is projected to become the largest application within the next few years. Unlike the jobs for which robots were previously used, these new applications do not merely benefit from the advanced capabilities of robot programming languages, they absolutely require them to achieve cost effective, reliable results.
For example, many applications now require vision systems to solve part presentation and fixturing problems. Other applications require that the robot interface directly with barcode readers, test equipment, and other intelligent devices. Fortunately, robot programming languages and systems are available to solve most of these problems. However, the solutions often require extremely complicated computer programs. A typical robot program now may consist of hundreds or thousands of conventional computer program instructions with only an occasional robot motion command. The introduction of robot programming languages has allowed the robotics industry to address new application areas, but the cost of this versatility has been a significant increase in programming effort.
The present invention provides a new approach to robot programming that greatly simplifies the integration, programming, and operation of robotic assembly cells. The preferred embodiment of the invention is called the Assembly and Information Management System (hereinafter called AIM), which is made by the assignee, Adept Technology, Inc. AIM allows, for the first time, programming of industrial robots using simple task-level statements such as "TRANSFER PART sn7404 TO u20".
The current best mode of the invention is a printed circuit board assembly system called AIM/PCB. The AIM system was also designed to handle other industrial processes, especially mechanical assembly (e.g., assembling electrical motors). The invention could also be adapted for other industrial processes such as chemical mixing and testing.